The Code Train

Where Neil Crosby talks about coding on the train…

RSS Entries

Hacking my body with the Wii Fit

Posted on May 14th, 2009 by Neil Crosby. Filed under Blog Posts.

Last Christmas, I bought myself a Wii and a Wii Fit with the express intention that this year I would finally lose some weight. At the time I was near on 20 stone (about 125kg), and was definitely feeling it.

Now, I’ve previously tried to lose weight. In fact it’s pretty much a yearly occurrence for me — I get the scales out, start weighing myself every day, get bored of writing numbers down and stop a couple of weeks later. This year though, I’ve weighed myself in every single day for the last 18 weeks, and so far I’ve lost 2 stone. So, what’s changed?

The big thing that should be pointed out is that I’m lazy. I don’t like having to do things that I shouldn’t have to. I never liked having to write down my weight every day, and getting round to drawing up little graphs with the data was just something I didn’t want to spend time doing. The fantastic thing I’ve found with the Wii Fit is that it does all that automagically. You just stand on it, get told you’re a fat bastard and then it draws you a graph of your progress. It’s seeing this graph going slowly but steadily downwards that’s giving me the incentive to carry on.

My routine with the Wii Fit is simple — I wake up in the morning, go to the toilet and then immediately do my weigh in. By having a fixed routine it’s far far easier for me to do the weigh in every day than if I was just doing it on an ad-hoc basis.

But what am I actually doing to lose weight? The truth is, not much. Remember? I’m lazy. Every day I walk 4 miles as part of my journey to and from work, but I’ve been doing that for the last 2 years anyway so that’s nothing new for me. Back when I first got the Wii Fit I was doing about half an hour of exercise on it every day, but that got boring quickly so I stopped doing it. Really, the thing that’s helped me lose the 2 stone is just cutting out all my snacks between meals. Yes that has required willpower, and my stomach does rumble from time to time, but I think that’s worth it.

That’s not to say that I’m starving myself. My aim for the year is to lose 4 stone over the 12 months, and if you look at the numbers that’s less that a pound and a half a week — essentially nothing. I’ve not really changed the rest of my diet — I’m still getting takeaways, buying dirty street burritos and eating all sorts of tasty food. The portions are slightly reduced, but not by much, and I’m not stopping myself from having anything that I want during mealtimes. This, I think, is key. I’m not on “a diet”, I’m simply trying to make small changes which over a long period of time will slowly reduce my weight. I want to keep this weight off, not have it yo-yo back on again, and the only way to do that is to do it slowly.

The one thing that does annoy me about the Wii Fit though is the fact that it’s an incredibly closed system. Essentially, anything that happens on the Wii Fit stays on the Wii Fit. There are no friend relationships between Wiis, there’s no way to get the data out onto the web. At Open Hack London last weekend, my plan was to write a parser to pull data out of a Wii Fit save file and start to do some interesting things with it. Unfortunately, none of the Wii save file parsers I found on the web worked for me, and I didn’t get anything completed. It’s definitely something I want to complete at some point though — being able to let my friends see how I’m progressing would be a great incentive to carry on carrying on.

Tags: , , ,

If you enjoyed this post, subscribe to The Code Train and read more when I write more.

5 Responses to “Hacking my body with the Wii Fit”

  1. For my university dissertation, I built a dieting website which, among many things, kept a record of your weight loss and plotted it against a graph to see what your BMI was and how you were progressing. It even had SMS support so you could just txt in your new weight (in metric or imperial) and that would automatically update.

    I’ve been thinking lately of rebuilding the system with the intention of sharing that data too. Obviously, it won’t be automated like the Wii Fit but if you could update your weight daily via SMS, Twitter, Facebook, an open API – whatever – it’s not that difficult to keep it up-to-date.

    Would you fancy teaming up to build something like this?

  2. I’m going to decline on this one I’m afraid Si – it really is the automation aspect of the WiiFit that I love, and unfortunately I don’t really have any spare time to be able to work on anything more than I already am right now. That said, it does sound like a cool little project, and I do look forward to seeing the fruits of your labour appearing over the next little while. :)

  3. Hi.

    I’ve begun hacking Wii Fit as well, to get the data out. I did get the data.bin file decrypted, so that I now have RPFitCap.dat, RPHealth.dat and RPWiiFit.dat. But parsing the files are not easy at all.

    Have you had any further luck with this process? (you can email me if you want – I assume you can see my address)


  4. Thomas Käfer Says:

    Well actually I found its not that hard to extract the data from the wii fit savegame, the hard work was done by others before me

    First, as Tobias already stated, you need to decrypt the savegame, which can be done with the tool called “tachting” from here:

    Then you can use the python script on your unencrypted savegame data, to convert this binary into a nice xml file –>

  5. Presumably the magazine doesn’t do deals with each source that it reproduces, so how does copyright law allow them to re-print editorial content that they don’t own without paying royalties?. . Also, can this law be applied internationally?.

Comments RSS

Leave a Reply

TheCodeTrain Theme by Neil Crosby, Powered by WordPress